PROBLEM TO BE SOLVED: To provide a method for producing a virus.SOLUTION: A production method includes steps of providing a host cell that has been infected by the virus and cultivating the infected host cell at two different temperatures. The virus produced by the cultivation step is subsequently collected. By using the dual temperature cultivation process, high titer and improved purity can be obtained. For many viruses, cultivation conditions can be substantially improved by using a two temperature profile. A higher temperature is applied for a first phase of the virus propagation, which accelerates the formation of infectious virus particles. In a second phase, a lower temperature is applied to maintain the initial high titer obtained in the higher temperature propagation period and to allow the formation of stable antigen which may be used for further production of immunogenic vaccines. It is a goal to provide improved growth conditions which do not affect the quality of the produced antigens for vaccination purposes.